[vortex] old problem? with vortex driver

[Donald Becker]

On Fri, 22 Mar 2002, David Dunlop wrote:

> I have a problem simuler to the one in these archives:
> http://www.tux.org/hypermail/linux-vortex-bug/1998-Jan/0002.html
> http://www.uwsg.iu.edu/hypermail/linux/net/0005.2/0171.html
>
> When I Download at High speeds I get this into my logs:
> Mar 21 20:49:55 zaphod kernel: eth0: Transmit error, Tx status register 90.

Transmit underrun.  This is rare.

> [root@zaphod log]# dmesg |grep 3c
> 3c59x: Donald Becker and others. www.scyld.com/network/vortex.html
> 02:0c.0: 3Com PCI 3c590 Vortex 10Mbps at 0xdf20. Vers LK1.1.16

Two interesting details: this is a really old 3c590, and it's 10Mbps
only.

Is there anything unusual about your system?

My driver releases default to programmed-I/O for the 3c590, and thus can not
encounter this error.  I'm not certain what the LK releases default to,
but at 10Mbps you should never get an underrun..

The user can set an option to use PCI bus mastering with my driver, but
the 3c590 series only had the hardware for weak single-linear-region
transfers.  Much like ISA DMA, setting up a short transfer takes more
time than just pushing the data out with PIO.  Using PIO was fine when the
3c590 was new and most PCI implementations had problems with bus
masters, but today you will get far better performance from any $10 10/100
NIC.

-- 
Donald Becker				becker@scyld.com
Scyld Computing Corporation		http://www.scyld.com
410 Severn Ave. Suite 210		Second Generation Beowulf Clusters
Annapolis MD 21403			410-990-9993